A Bird Blog with Kate St. John

Archive for November, 2010

If I was to place a bet on crows I’d wager they didn’t spend last night in the plane trees on University Place in Oakland. I’d win this bet because of what I found there less than 24 hours ago.

Yesterday morning I got a call from a Pitt employee who tracked me down out of concern for the peregrines. Marian had found a very large raptor standing on the ground near Soldiers and Sailors Hall on University Place. The bird would not fly away and there were feathers scattered on the ground beneath its feet. She was concerned that this was one of the peregrines and that it was injured and unable to fly away.

The situation sounded like a red-tailed hawk on a kill but you never know. I was happy to help and went over to check.

As I arrived at University Place I noticed a lot of crow poop on the sidewalk beneath the London plane trees. The closer I got to the site, the more poop there was.

When I reached the place Marian described I didn’t find a large bird on the ground but I could tell exactly where he’d been. Right next to the sidewalk was a big pile of crow feathers, a few crow bones and a crow’s skull and beak. Whoa! Someone had been eating crow!

I imagined the fear in the flock when that raptor arrived. I’m sure it scared the poop out of them and they left in a hurry. No wonder the sidewalk was gross.

Now there’s one less crow among the 10,000+ who roost in Pittsburgh and those still living can see how he died.

I usually don’t chase rare birds because I am so disappointed when I drive a long way and don’t find what I came for, so in December 2005 when Andy Markel reported a juvenile prairie falcon in the open fields of Cumberland County north of Shippensburg I did not go see it.

Over the next few weeks Andy and others found and photographed the prairie falcon again and again. It was so far out of range that many wondered if it was a falconer’s bird but no one could prove it. The bird stayed through the winter and then was gone.

Prairie falcons (Falco mexicanus) are western birds of cliffs and open country. They’re the same size and shape as peregrines except that they’re pale brown and white with dark axillaries (armpits) and pale heads. They range from California to Colorado, from southern Canada to Mexico. They never come to Pennsylvania.

But this one does. Every winter the prairie falcon returns to the same place on Mud Level Road. Now, of course, it’s an adult. In February 2008 it was found so easily that many birders made the trek to see it and even discovered that it roosts at a quarry a mile away from its daytime haunts. (Prairie falcons like cliffs just as much as peregrines do.)

Still I did not go to see it. The 3+ hour drive from Pittsburgh was too long for the disappointment I was bound to encounter.

But this year the falcon came back early — November 20 — and I was going to be in Hummelstown for Thanksgiving, only an hour away. Saturday morning, November 27, was my only chance to chase it.

Long before dawn I drove to Cumberland County and found two other birders already at the intersection of Mud Level and Duncan Roads. Neither had found the bird but with more eyes on the sky we stood a better chance.

Soon we saw a falcon hazing the pigeons northwest of Mud Level but even through a scope the bird was impossible to identify. Jonathan Heller and I drove to Brinton Road for a better look but could not relocate the bird. Mike Epler stayed behind, then drove the circle. No luck.

Back and forth we searched. Jonathan and I tracked a falcon that didn’t look quite right but it was our best candidate. We finally caught up to it just as it landed in a tree on Brinton Road. We screeched to a halt, jumped out of our cars and identified … a merlin.

At any other time and place a merlin is a good find but we were disappointed. This was made worse when Mike drove up and told us he had just seen the prairie falcon at Mud Level and Duncan. He had watched it retrieve a mourning dove dropped by a harrier, then perch and eat the prey close enough for a great look.

Aaarrrgg! We went back to our starting point but the bird was gone.

Jonathan was preparing to leave so I took a slow drive down Mud Level Road contemplating the ephemeral nature of rare birds. I told myself that on this trip I’d heard horned larks and seen a merlin, kestrels, northern harriers and red-tailed hawks — and that should be enough. Sigh.

No point in looking anymore. Sigh.

I drove away slowly down Duncan Road.

A pale brown hawk, very pale, on a hay bale, caught my eye. It had its back to me and was eating. Oh my! I pulled off the road and parked near the hay bale. I rolled down the passenger window and had an excellent view of the prairie falcon as it ate a bird.

The falcon looked around, his cere and eyerings yellow, his legs brighter yellow, his head quite pale.

Though I stayed in my car I made him nervous. He bobbed his head, then picked up his prey and flew to another hay bale. In flight I saw his dark axillaries. Again he was nervous, flew down to the ground, then eventually northwest across Mud Level Road. Good bird!

I’ve now seen every falcon that normally occurs in North America except the aplomado. (It occurs from Mexico to South America, rarely in the southwestern U.S.)

Needless to say the bird in this photo is not the one at Mud Level but it captures his look and posture. For an even better look, click here for a flight photo and you’ll see the dark feathers under the wing.

(photo of a prairie falcon by Matt MacGillivray via Wikimedia Commons. Click on the photo to see the original)

Here’s a beautiful picture of a bird we rarely see in southwestern Pennsylvania. When we do it’s alone, flown off course while its companions migrated to the Atlantic coast on a route far north of Pittsburgh.

This is a brant, a small goose that nests in the Arctic and winters at the coast. It resembles a Canada goose except that it’s much smaller, has a stubby bill, the shortest tail of any goose, and a dark head, neck and chest.

Sometimes brant, especially lone birds, hang out with Canada geese. This may have saved them from extinction. In the early 1930’s the brant population declined dangerously because the only food they ate — a marine plant called eelgrass — was in short supply. Then they changed their diet to include grass and grain from agricultural fields, a habit they may have learned from Canada geese. But they still prefer eelgrass.

If you want to see a lot of brant, visit the coast in winter. Otherwise the only reliable place to find them in Pennsylvania is at Lake Erie during their October-November migration.

Today’s anatomy lesson was inspired by Michelline who asked why she sees only peregrines’ neatly folded talons when they fly. Where do the rest of their legs go?

The bones in birds’ legs are of nearly equal length and the hinges are opposite like an accordion. This has two advantages: They can lower themselves straight down to sit on their eggs without tipping over and they can retract their legs to a nearly flat position in flight.

To illustrate this I’ve highlighted the legs in red and numbered the joints:

The blue arrows show how birds fold their legs when they fly. In step (a) the thigh and shin fold up flat to the body and are hidden in the body feathers. In step (b) the foot and toes can do several things:

In summer the plant is all white, almost translucent, and its flowers bend down to face the forest floor. It has no chlorophyll and no leaves, just scales on its stem, because it lives on nutrients from fungi in the humus (leaf litter).

Indian Pipe’s white appearance earns it the nickname Ghost Plant. Click here to see its summer form.

In winter Indian Pipe is brown and stands about six inches tall. Its flower head is now a five-sided woody seed capsule that points straight up. The scales on its stem are wrinkled and look like the remnants of leaves.

Because it’s a perennial Indian Pipe is likely to bloom in the same place next year.

Much to my amazement a pigeon has been frequenting the peregrine falcon nest at the University of Pittsburgh. The Aviary’s snapshot camera took his picture as he moved around the nest on November 15th and 19th.

The resident peregrines, Dorothy and E2, are at the Cathedral of Learning every day but not often at their nest. Apparently they aren’t paying attention to this corner of their domain.

Or maybe they’re in a timeshare agreement and this pigeon bought the third week of November?

Who knows? He just better be careful not to be at the condo when the real owners return or they’ll have him for dinner.

Click on the pigeon’s picture to see Dorothy and E2 at the nest earlier this month.

(photo from the National Aviary snapshot camera at University of Pittsburgh)

The trees are bare in Pittsburgh. Last week we had a day of rain followed by gusty winds … and that was that. All gone by November 18.

Now that the leaves are down you can see what they hid all summer. Easiest to find are large nests of sticks or leaves but there are plenty of other treasures, some large, some small.

Yesterday I found this hornets’ nest. It’s so far up in the maple tree that my photo doesn’t give you a sense of scale but it’s huge. Only a bird, a snake, or a squirrel could reach it but they won’t do so while the nest is occupied. Hornets vigorously defend their nests!

By now the hornets are gone. Most have died and the juvenile queens have left to hibernate underground, under logs, or in hollow trees. Since hornets use their nests for only one breeding season, this is the time of year when it’s safe to collect a hornets’ nest for display.

Take time now to look for summer’s secrets. By winter’s end the nests will be weathered and broken. Look hard and you might find the tiny, camouflaged cup nest of a ruby-throated hummingbird.